• L. S. Cardman, L. Harwood
  Jefferson Lab, Newport News, Virginia

CEBAF is a 5-pass, recirculating cw electron linac operating at ~6 GeV. The 12-GeV Upgrade is a $300M project anticipated to receive Critical Decision 2 approval in late summer of 2007 and begin construction activities in 2008; funding for the project is provided by the DOE Office of Nuclear Physics which will double the beam energy. The new energy reach will permit significant extensions in research into non-perturbative aspects of QCD. Areas of interest are Generalized Parton Distributions (GPDs), measurements at high-xBjorken, and the use of hybrid mesons to explore the nature of quark confinement. The upgrade includes: doubling the accelerating voltages of the linacs by adding 10 new high-performance cryomodules plus the requisite expansion of the 2K cryogenics plant and rf power systems, upgrading the beam transport system from 6 GeV to 12 GeV capability through extensive re-use of existing hardware, adding one recirculation arc, adding a new experimental area and the beamline to it, building new experimental equipment for the GPD, high-xBjorken, and hybrid mesons programs. The presentation will touch on the science and give some details of the accelerator plans.

• Y. Zhang, S. A. Bogacz, P. B. Brindza, A. Bruell, L. S. Cardman, J. R. Delayen, Y. S. Derbenev, R. Ent, P. Evtushenko, J. M. Grames, A. Hutton, G. A. Krafft, R. Li, L. Merminga, J. Musson, M. Poelker, A. W. Thomas, B. Wojtsekhowski, B. C. Yunn
  Jefferson Lab, Newport News, Virginia
• V. P. Derenchuk
  IUCF, Bloomington, Indiana
• V. G. Dudnikov
  BTG, New York
• W. Fischer, C. Montag
  BNL, Upton, Long Island, New York
• P. N. Ostroumov
  ANL, Argonne, Illinois

Experiments on the study of fundamental quark-gluon structure of nucleons require an electron-light ion collider of a center of mass energy from 20 to 65 GeV at luminosity level of 10³⁵ cm^-2s-1 with both beams polarized. A CEBAF accelerator based ring-ring collider of 7 GeV electrons/positrons and 150 GeV light ions is envisioned as a possible next step after the 12 GeV CEBAF Upgrade. The developed ring-ring scheme takes advantage of the existing polarized continuous electron beam and SRF linac, the green-field design of the collider rings and the ion accelerator complex with electron cooling. We report results of our design studies of the ring-ring version of an electron-light ion collider of the required luminosity.